The invention relates to an apparatus for damping rotational vibrations in a power train.
Such an apparatus is known from DE 195 11 188 C2. It concerns especially free-wheel pulleys which dampen rotational vibrations in a power train by means of a free-wheel clutch. The power train or traction mechanism drive therein can comprise a pulling strap, especially a profiled pulling strap, engaging at a correspondingly profiled drive pulley.
In the known apparatus the free-wheel clutch is formed as a roller free-wheel with axially arranged rollers.
For example in a reciprocating piston internal combustion engine there result, due to the pulsating operation, rotational irregularities which are transferred onto the power train and thereby to the driven unit. By means of the known solution, though, the descending branches of the rotational irregularity can be filtered out by means of the free-wheel clutch by free rotation of the rotor of the driven unit. However, with an increase of the number of revolutions of the driving element, that is particularly the reciprocating piston internal combustion engine, the rotor of the driven unit is again driven in a pulsating manner by the reaction or actuation of the free-wheel. This still leads to rotational vibrations in the driven unit and to an increased pulling force in the power train, especially in the driving strap. By the invention these disadvantages shall be eliminated and a corresponding decoupling shall be obtained.